Work holding devices, such as vices and clamps are necessary for holding a workpiece immobilized while further machining or the like is done on the piece. The standard vice having parallel opposed jaws is well suited for objects having planar surfaces. Unfortunately such a vice cannot adequately secure a workpiece having a contoured surface. The use of contour conforming clamping devices has made it possible for irregularly shaped objects to be adequately secured without creating pressure points which may cause damage to the workpiece.
A number of such contour conforming clamping devices are known in the prior art. Many of them employ a plurality of finger-like members which adjust to the shape of the object over its irregular surface. One such device, disclosed in the patent issued to Peterson, U.S. Pat. No. 2,754,708 shows spring-loaded members which exert pressure against the workpiece. More sophisticated devices are shown in patents issued to Blazek, U.S. Pat. No. 2,882,771 and patent issued to Pevar, U.S. Pat. No. 3,386,102. These devices employ plungers which rely on hydraulic fluid pressure to exert force on the workpiece. These fluid systems work well in that they can more evenly apply high pressure to the workpiece without causing damage at any one point. The fluid system, however, requires expensive milling of the vice jaw housing to receive the plungers and to prevent loss of hydraulic fluid. In addition, should the jaw members be damaged or become worn through repeated contacts with the workpiece, the device must be completely disassembled to replace these parts.
The present invention provides a fluid operated system for creating a contour conforming vice jaw which is simple to construct and provides for easy replacement of elements.